A technology of a lubricant feed mechanism for an engine has been known by which lubricant is fed to a cam of a valve gear through a cylinder head, a camshaft, and a cam cap. Examples include JP-A-2010-164009.
A lubricant feed mechanism for an engine described in JP-A-2010-164009 includes a cylinder head having a hearing, a camshaft rotatably supported by the bearing, a cam cap fixedly attached to the cylinder head from the upper side to hold the camshaft therewith, and a cam shower pipe connected to an upper portion of the cam cap.
Further, the lubricant feed mechanism includes a communicating oil passage from an oil gallery of the cylinder head to the camshaft (bearing), an oil passage penetrating the camshaft (cam journal), and a communicating oil passage that is provided in the cam cap and connects the camshaft to the cam shower pipe.
In the lubricant feed mechanism thus configured, lubricant that circulates in the oil gallery can be fed to a plurality of cams of a valve gear through the cylinder head, the camshaft, the cam cap, and the cam shower pipe. Thus, lubricant of a substantially equal amount is fed to the plurality of cams by extracting lubricant from the oil gallery of a relatively large diameter, i.e., with a less pressure loss.
However, according to the technology described in JP-A-2010-164009, the cam shower pipe for feeding lubricant to the cams is positioned at an upper portion of the cam cap. Typically, the upper portion of a cam cap is covered with a cylinder head cover, and not much space is left above the cam cap. Hence, in actually applying the technology described in JP-A-2010-164009, the cam shower pipe may interfere with another member, such as a baffle plate positioned at the cylinder head cover side, which may involve additional design changes to avoid the interference.